025-0508 - Journal of Pyrotechnics, Issue Nos. 9

Titles and Abstracts for Issue No. 9, Summer 1999

Organic Fuels: Composition and Formation Enthalpy-Part I Resins, Charcoal, Pitch, Gilsonite, and Waxes
Will Meyerriecks [Tampa, FL, USA]


Abstract: The utilization of free energy minimization computer programs in areas of combustion research is likely to increase in the future. These programs require the specification of the reactant chemical formulas and their respective formation enthalpies as part of the input data set. Frequently, for common compounds, the values required are readily available in handbooks. Complex organic compounds or poorly characterized mixtures may not have the required data available in a directly usable form. This article evaluates a variety of organic fuels used in pyrotechnics from the perspective of establishing useful chemical formulas and formation enthalpies. Along the way, it is the author’s intention to simplify the methods used, to illustrate how many disparate sources of information may be drawn upon to achieve the estimation of the required values, and to demonstrate that each of the methods used is itself relatively easy to perform or calculate.

Keywords: acaroid resin, anthracene, Benson group, bitumen, charcoal, enthalpy of formation, free energy minimization, organic fuel, gallic acid, gilsonite, hexachlorobenzene, hexamethyene tetramine, hexamine, higher heating value, naphthalene, paraffin, pitch, polyvinyl chloride, polyvinylidine chloride, shellac, sodium benzoate, sodium -salicylate, stearin, bees wax, xanthorrhoea
Number of pages = 19.

The Hazards Posed by Fragments from Rupturing Steel Fireworks Mortar Tubes - Predictions from a Computer Model
M. R. Edwards, S. G. Myatt [ Health and Safety Laboratory, Harpur Hill, Buxton, Derbyshire, United Kingdom, SK17 9JN] and S. Ellis


Abstract: Fragments with masses of up to 100 g and velocities of up to 510 m/s can be produced from spiral-wound mild steel mortar tubes when firework maroon shells of diameters up to 150 mm are exploded in them. External ballistics calculations indicate that such fragments could travel up to 165±60 m, and possibly 30% further if ricochets on a concrete surface take place. Calculations indicate that these fragments possess sufficient kinetic energy density to penetrate the skin of spectators on landing. In addition, large slow-moving fragments of up to 7 kg are also produced and these could inflict blunt trauma injuries on operators.

Keywords: computer-modeling, mortar fragment, steel mortar fragment, mortar, fireworks explosion, velocity, steel fireworks mortar, safety, mortar explosion, salute-in-mortar explosions
Number of pages = 8.

An Introduction to Chemical Thermodynamics Part 1 - Matter, Energy and the First Law
Barry Sturman [Mount Waverley, Victoria , Australia]


Abstract: This is the first in a series of articles presenting an introductory outline of chemical thermodynamics and chemical kinetics, with emphasis on those aspects of particular relevance to pyrotechnics. A brief comment on the molecular theory of matter is followed by a discussion of basic mechanics to introduce the concepts of work and energy. The non-conservation of mechanical energy leads to the idea of heat as a form of energy, and to the Law of Conservation of Energy. The concepts of temperature and thermal equilibrium are then introduced. An introduction to thermodynamic systems, thermodynamic states and state functions is presented. The first Law of Thermodynamics is introduced as a statement of the Law of Conservation of Energy in terms of changes in internal energy, heat and work. The enthalpy is shown to be a useful thermodynamic state function; the enthalpy change in a process corresponds to the heat transferred between a system and its surroundings at constant pressure. Calculations of the heat transferred in chemical reactions are demonstrated. A Table of standard enthalpies of formation of a range of pyrotechnically interesting materials is included for use in such calculations.

Keywords: enthalpy, hea -energy, thermochemistry, thermodynamics
Number of pages = 21.

Performance Study of Civil War Vintage Black Powder
K. L. & B. J. Kosanke [PyroLabs, Inc., Whitewater, CO, USA] and F. Ryan


Abstract: A sample of Black Powder dating to the time of the US Civil War was harvested from cannon balls uncovered during an excavation on what had previously been the grounds of the Allegheny Arsenal. A portion of this powder was eventually made available for an investigation of its properties. It was found to be in excellent condition, both physically and in its performance. Physically, it is essentially indistinguishable from high quality Black Powder of current production. Its performance under conditions replicating its normal use was only slightly less than that produced by a high quality powder of current production.

Keywords: Civil War vintage Black Powder, Borman fuse, quickness test, Black Powder, quickness tester, eprouvette
Number of pages = 6.

The Rare Earths As Possible Flame Color Agents
Barry Sturman [Mount Waverley, Victoria , Australia]


Abstract: Colors observed when solutions of scandium, yttrium and the lanthanide elements were sprayed into an inductively coupled plasma are reported. It is suggested, but without experimental evidence, that the colors seen in the lower temperature regions of the plasma (and in a pre-mixed air-acetylene flame) might also be produced by appropriate pyrotechnic mixtures. The color-emitting species (metal monoxide molecules) are remarkably stable, as shown by the dissociation energies of the M-O bonds. These monoxides might be able to exist in useful concentrations at the high temperatures of the glitter flash reaction, thus providing colored glitter. The possibility of using yttrium or erbium, or corrosion resistant alloys thereof, to produce red or green sparks is also suggested.

Keywords: rare earth color agents, colored flame, flame color, colored glitter, colored spark
Number of pages = 5.

Studies on Low Smoke Photoflash Compositions
R. Hancox, M. Wilson and B. Whiffen
[Weapons Systems Division, Aeronautical and Maritime Research Laboratory (AMRL), Melbourne, Australia]


Abstract: [Reprint originally appeared in: Proceedings of the 19th International Pyrotechnics Seminars, Christchurch, NZ, Feb. 1994.]There have been numerous reports in recent years of problems with the use of certain pyrotechnic photoflash compositions in noise simulators. The most common has been the gassing problem caused by the oxidation, during storage, of the magnesium metal fuel. In addition the quantity of particulate smoke produced by the combustion reaction can cause a number of undesirable effects when the simulators are deployed in confined environments during training operations. A study has been undertaken to investigate compositions which use alternative reactants to generate the pyrotechnic effects. The relative noise, light and smoke emissions of the compositions have been measured. Preliminary results suggest that a formulation which uses powdered hexamine as the fuel may offer a satisfactory alternative as the filling in noise simulators.

Keywords: photo-flash, low smoke, low smoke photoflash
Number of pages = 8.

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